Wrought-metal pole-arm.



PATENTED' JULY 23, 1907.

M. BsH ARRISO WROUGHT METAL POLE ARM.

APPLIOATION PI QLBD JAN- 23, 1907.

'2 SHEETS-11331 1.-

PATENTED JULY 23, 1907.

' M. E.- HARRISON;

WROUGHT METAL POLE ARM. APPLIUATION FILLED JAN. 28, 190i MARTIN EMMITT HARRISON, or PARNASSUS, PENNSYLVANIA.

fwROUGHT-M TAL POLE-ARM.

Specification of Letters Patent.

Patented July 23, 1907.

Application filed nuary 28, 1907. Serial No. 354,453.

To all whom it may concern:

Be it known that I, MARTIN EMMITT HARRIsON, a citizen of the United States, residing at Parnassus,- in

the county of Wcstmoreland and State of Pennsylvania,

have invented certain new and useful Improvements in \YroughtMetal Pole-Arms; and I do declare the followingto be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification;

This invention relates to a new article of manufacture, and it comprises the making from a sheet of wrought metal, of a telegraph pole cross-arm, which will be strong, durable and of simple construction, adapted to take the place of the wooden arm now ingeneral use, together with means for supporting or attaching the insulator pins in position thereon, a means for securing said arm to the pole, also thepeculiar form oi'construc tion to give the arm the greatest lateral and direct strength, the bending and shaping of the top to form a water-shed for the preservation of the arm, together with other of certain details of construction, as will be iully described hereinafter.

In the accompanying drawings ;-Figure'1 is a side elevation of my improved cross-arm for telegraph poles, a part oi which is shown in section and one. of the ends broken away. Fig. 2 is a plan view of the same, also having a part in section. Fig. 3 is a sectional end elevation taken on the line y y, of Fig. 2, said view being shown on a larger scale. Fig. 4 is an enlarged side sectional elevation of a portion of the arm, showing a means whereby the. insulator pins may be attached thereto,

Fig; 5 is a side elevation of a modified form of the crossarm, showing the construction used in connection with wooden insulator pins such as are now in common use,

Fig. 6 is an inverted plan view of the same. Fig. 7 is a plan view of a small portion of the arm, showing the flanged openings for the reception of the shank of the insulator pin. Fig. 8 is an enlarged end elevation of the cross-arm, showing an insulator pin in position.

To construct a telegraph pole cross-arm in accordance with my invention, I provide a piece of sheet metal, such as steel, of the proper. width and length, and by means of suitable dies and press, bend the said sheet to a form substantiallyflU shaped in cross section, (see Figs. 1 2 3 and h) leaving an open bottom, the sides 1 being parallel with each other, andthe top higher along its central longitudinal line than at either side, to form a water-shed 2. This water-shed 2, may be in the form of a curve, as at Fig. 3 or with angular sides ar-; ranged to precipitate the water during rain storms; Formed through the top of the cross-arm and-at regular intervals, are openings for the reception of the shanks oi the insulator pins 5, which are now manufactured,

for the purpose of sustaining wires, in two forms, the one of metal and the other of wood, both of which are shown in the drawings. These metal pins 5 are formed with a flanged threaded shank, and are attached and made rigid with the cross-arm by means of a nut, (not shown) 'or otherwise. These metal pins I prefer to attach to the arm by means of a small casting, which, consists of a body-portion 10, arranged within the arm and extending from one side to the other, said casting having a central threaded orifice for the reception of the threaded shank of the insulator pin 5. With this abovedescribed means of attaching the insulator pins 5, it will not be necessary to permanently fix the same to the arm by rivets or otherwise, as said pin whenscrewed tightly in position and the casting 10 extending from one side wall to the other, the threaded shank and fiangeoi the pins will bind the parts rigidly together.

The advantage of this means of attaching the pins 5 in position on the arm, will berto stiffen and support the side walls against lateral pressure, the casting 10 being made to conform with the inner contour of the arm in' I all respects and to fit neatly therein. Surrounding the openings 6 for these insulator pinsis a slightly elevated boss 4, pressed outward from the metal to form a flat surface at right-angles to the plane of the sides 1 of the arm, and serves as a bearing for the flange of the in-- sulator pin. p

The sides 1' oi thearm are formed with inwardly pressed ribs 3, and extend from the ends of said arm inwardly to points a short distance at either side of the longitudinal "center of the same; the object being to stifien the side wallsiby thus bending the metal) against lateral strain. To attach the cross-arm to the telegraph or other pole, bolt openings are formed through the sides 1, at'the middle or center of its length, the one opening in direct horizontal linewith the other and through which a bolt 7 is passed, the said bolt being fitted with a separating piece 9 and projected through said pole and secured by a washer ing piece 9, I prefer to term from a piece oi pipe or and nut, in a manner commonin the art. This parttube, and is adapted to fit snugly within said arm 1 and held in position by the bolt 7 passing therethrough. This parting piece 9 will hold the sides in lineagainst the strain caused by the tightening of the bolt 7. To further. support the cross-arm in position I on the pole 8, diagonal arranged braces 11 are attached to one of the'sides of the arm by rivets 12 and the free ends attached tothe pole some distance below the level of said arm.

The above description relates exclusively .to that form of a cross-arm wherein metal insulator'pins 5 are used, and in order that wooden pins 5 maybe attached-and used with this class of cross-arm, it is necessary to modify the details of construction respecting the meansfor supporting said wooden pins thereon This modified form I have shown at Figs. 5 6.7 and-8,

of the drawings, in which the cross-arm is formed from a plate or sheet of metal bent substantially the same as that previously described, and having the side walls 1 at a portion of the middle substantially U shaped in cross section, and a portion of each lower half of said sides bent inwardly, leaving a narrow space 14, which construction serves the double purpose of strengthening the arm against direct and. lateral strains, and affords a means for supporting the lower end or shank of the wooden insulator pins 5,

-the metal at which points-being expanded to fit "neatly about opposite sides of said pins, as will be best seen by reference to Figs. 5 6 and 8, of the drawings. The water-shed 2 and bosses 4 are the same as before described, and if it is desired, the metal about the perimeter of the openings 6 forthe insulator pins, may be flanged downward, (see Figs. 7 and 8) andmade to present a broad surface for the support of the upper part of the shank of said pin. The braces 11 may be attached to one oi the side walls by rivets 12, or said rivets passed through both walls, as shown at Figs; 5 and 6. The means employed for attaching this form of cross-arm to the pole 8, is identical wit thatof the other form shown and described.

These arms are made in various lengths and strength Another and important advantagein this wrought metal arm covered with a weather-proof material is,

that it is practically indestructible, and times the life of the wooden arm.

This above-described pole arm is made from sheet metal, cut in blank form, and by several processes of bent by dies and presses into the proper form, and should not be classed with arms forithe same purpose, made fromrolled shapes, such asI beams, chanhas several.

bending, flanging, ribbing, &c., either cold or hot, 7

nel bars, angle bar, &c., which latter shapes are made under an altogether different process and are produced at several times the cost. 1 It is obvious that this sheet metal cross-arm may be formed in a variety of different shapes best suited to the circumstances under which it is used. Therefore I I do not wish to confinemyself to the exact details of construction, but wish toclaim all such modified forms as would come properly Within the general scope of the invention.

Having thus described my invention, what I claim, and desire to secure by Letters Patent,

1. As a new article of manufacture, a pole arm of pressed sheet steel.

2. As a new article of manufacture, a pole arm .con structed' from a single piece of sheet steel pressed into form 3. Ash new article of manufacture, a pole arm of sheet steel-pressed into form and folded longitudinally to form spaced sides and connecting web.

In testimony whereof, I atlix my signature, in presence of two witnesses.

, MARTIN'EMMI'lT HARRISON.

Witnesses:

WALG. WALTER, O'r'ro A. HENSEL. 

